How to press "Back" button in UINavigationController programmatically

I have a UIViewController called FriendsViewController inside a 开发者_高级运维UINavigationController. And a second UIViewController called FriendsDetailedViewController. When navigating from the first view controller to the second, I want to programmatically press the Back button when needed. How to do this?

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Simply use

[self.navigationController popViewControllerAnimated:YES]

from FriendsDetailedViewController. Your view will be popped out i.e. the behavior of back button.

Note that it returns UIViewController on normally, and returns nil if there is nothing to pop.

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If by pressing "Back" button you mean just to go to the previous view controller, you can just call:

[self.navigationController popViewControllerAnimated:YES];

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Here is the swift method

if let navController = self.navigationController {
    navController.popViewControllerAnimated(true)
}

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Swift 5

 self.navigationController?.popViewController(animated: true)

Usage in a code snippet:

func unwindViewController() {
    self.navigationController?.popViewController(animated: true)
}

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1) When you pop in current NavigationController Then

In Swift

self.navigationController?.popViewControllerAnimated(true)

Objective C

[self.navigationController popViewControllerAnimated:YES];

2) When you back another Navigation controller Then

In Swift

let story = UIStoryboard(name: "Main", bundle: nil)
let pushVC = story.instantiateViewControllerWithIdentifier("PushVC")
let navigation = story.instantiateViewControllerWithIdentifier("homeNavigation") as! UINavigationController
navigation.pushViewController(pushVC!, animated: true)

In Objective C

UIStoryboard* storyboard = [UIStoryboard storyboardWithName:@"storyBoardName" bundle:nil];
pushVC* ObjectOfPushVC = [storyboard instantiateViewControllerWithIdentifier:@"pushVC"];

[self.navigationController pushViewController:ObjectOfPushVC animated:YES];

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Here is how I did it in Swift 3

_ = self.navigationController?.popViewController(animated: true)

_ is used to suppress the ugly warning generated by XCode.